Patchwork [x86-Atom] Enabling look-ahead scheduling feature for Atom processors

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Submitter Igor Zamyatin
Date Aug. 28, 2012, 9:24 a.m.
Message ID <CAKdSQZmU+dduhNtSu-iSXnuPQ=PjtJB_bDghQy9KGsqwBcOZJQ@mail.gmail.com>
Download mbox | patch
Permalink /patch/180386/
State New
Headers show

Comments

Igor Zamyatin - Aug. 28, 2012, 9:24 a.m.
Hi!

I'd like this patch (original version at the bottom) also to be
backported into 4.7.

Is it safe to backport?

On Fri, Aug 24, 2012 at 11:35 AM, Uros Bizjak <ubizjak@gmail.com> wrote:
> On Fri, Aug 24, 2012 at 9:22 AM, Igor Zamyatin <izamyatin@gmail.com> wrote:
>
>> Following change enables look ahead feature in the code scheduler for
>> Atom processors. This gives quite reasonable gain for some benchmarks
>> for mobile market.
>>
>> Overall compile time increase for SPEC2000 is about 1%.
>>
>> Regtested for x86_64 and also bootstrapped with "--with-arch=core2
>> --with-cpu=atom"
>>
>> 2012-08-23  Yuri Rumyantsev  <ysrumyan@gmail.com>
>>
>>         * config/i386/i386.c (ia32_multipass_dfa_lookahead) : Add
>>         case for Atom processor.
>
> OK.
>
> Thanks,
> Uros.

Original patch:
Uros Bizjak - Aug. 28, 2012, 9:34 a.m.
On Tue, Aug 28, 2012 at 11:24 AM, Igor Zamyatin <izamyatin@gmail.com> wrote:

> I'd like this patch (original version at the bottom) also to be
> backported into 4.7.
>
> Is it safe to backport?

Looks safe to me.

OK if there are no objections from RMs in the next 24h.

Thanks,
Uros.

Patch

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 976bbb4..331e29a 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -24103,6 +24103,7 @@  ia32_multipass_dfa_lookahead (void)
     case PROCESSOR_CORE2_64:
     case PROCESSOR_COREI7_32:
     case PROCESSOR_COREI7_64:
+    case PROCESSOR_ATOM:
       /* Generally, we want haifa-sched:max_issue() to look ahead as far
         as many instructions can be executed on a cycle, i.e.,
         issue_rate.  I wonder why tuning for many CPUs does not do this.  */